# Life Example

---


if Johnny want to buy the delicious coffee, how network help with Johnny.

## Overview

Ok Now, he have to use transport layer to transport his packet, and this way he have two options.
One is TCP. another is UDP

Versus
tcp -> reliable
udp -> more fast

port 443 -> https
port 80 -> http


**Network layer**

deal with ip address and routers

**Data link layer**

We're deal with mac Address we're giving our switch direction to the next stop

the ip address information inside a new layer 2 header and he change the source and destination mac address


Quiz 1


Ans : a c e

B and D is impossible
B: Because delivery should be layer 4 to deal with, ensuring -> TCP
D: logical and physical addressing -> probably is layer 2
f: It is presentation layer 6


Ok this problem is fucking easy, if you know 3-way handshake

Obviously, the answer is B